Filler coupling and corresponding receptacle and filling method

ABSTRACT

A filler-withdrawal coupling for a pressurized gas receptacle comprising a body defining an internal filler circuit between an upstream end designed to be connected to a packaging connector and a downstream end designed to be connected to a receptacle, the coupling comprising an isolation valve that can move relative to a seat between an upstream position for closing the circuit and a downstream position for opening the circuit, said isolation valve being moved to its upstream position by a return member, the coupling also comprising a dust-prevention valve placed upstream of the isolation valve, said dust-prevention valve being able to move relative to the body between an upstream position for closing the upstream end of the circuit and a downstream position for opening the circuit upstream end, said dust-prevention valve being moved to its upstream position by a return member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/168,532 filed Jun. 24, 2011 which claims the benefit of priorityunder 35 U.S.C. §119 (a) and (b) to French Application No. 10 55605,filed Jul. 9, 2010, the entire contents of which are incorporated hereinby reference.

BACKGROUND Field of the Invention

The present invention relates to a filler coupling, a tap, a pressurizedfluid receptacle and a filling method using such a coupling.

The invention relates more particularly to a filler coupling for apressurized gas receptacle designed to interact with a packagingconnector in order to allow said receptacle to be filled, the couplingcomprising a body defining an internal filler circuit between anupstream end designed to be connected to a packaging connector and adownstream end designed to be connected to a receptacle, the couplingcomprising an isolation valve that can move relative to a seat betweenan upstream position for closing the circuit and a downstream positionfor opening the circuit, said isolation valve being moved to itsupstream position by a return member, the coupling also comprising adust-prevention valve placed upstream of the isolation valve, saiddust-prevention valve being able to move relative to the body between anupstream position for closing the upstream end of the circuit and adownstream position for opening the circuit upstream end, saiddust-prevention valve being moved to its upstream position by a returnmember.

The present invention concerns in particular a filler couplingcomprising in series, from upstream to downstream (in the direction of afilling with gas), a dust-prevention valve and an isolation valve.

Related Art

The dust-prevention valve is provided notably to form a barrier upstreamof the isolation valve to prevent or limit the intrusion of particles orof dust that may damage the sealing of said isolation valve.

A removable stopper or a dust-prevention valve is usually a goodprotection against the intrusion of foreign bodies into a fillercoupling. However, this protection is not usually sufficient because,when the dust-prevention valve is open, particles can enter during thefilling operation. These particles might in certain circumstances bebrought in by the filling tool that delivers the filling gas.

This contamination of the isolation valve may cause a considerableleakage rate over the life of the product on which this filler couplingis installed. This is explained by the fact that the sealing zone of thecontaminated isolation valve (dust, particles etc.) loses a largeproportion of its sealing capability. This risk of intrusion ofparticles is increased when the filler coupling is vertical (fillingfrom above).

Another solution consists in providing a filter for solid particles inthe coupling upstream of the isolation valve. This makes it possible totrap particles or dust upstream of the isolation valve but does not makeit possible to actuate the opening of the isolation valve by mechanicalcontact (the filter in fact forming a mechanical barrier for a valvedriver).

Another solution consists in providing a filter downstream of theisolation valve. This allows the mechanical actuation of the isolationvalve and provides dust protection for downstream of the isolation valve(the inside of the tap and the inside of the receptacle). However, theupstream end of the isolation valve is then subject to contamination byparticles or dust that can affect its sealing.

SUMMARY OF THE INVENTION

One object of the present invention is to alleviate all or some of thedrawbacks of the prior art listed above.

For this purpose, the coupling according to the invention, moreoverconforming to the generic definition given to it by the above preamble,is essentially characterized in that the dust-prevention valve supportsa filter interposed on the path of at least a portion of the fluid thattravels between the upstream and the downstream of the circuit, thefilter being able to move with the dust-prevention valve.

Therefore, according to the invention, a filtration device such as oneor more filters is incorporated into a movable part which forms anupstream dust-prevention valve.

In this way, a double protective barrier is provided upstream of theisolation valve. Specifically, the body of the dust-prevention valveforms a first movable stopper at the upstream inlet of the coupling andthe filter forms a second barrier which traps the particles when thedust-prevention valve opens the inlet of the coupling.

Moreover, this architecture with double valves and movable filter formsan effective protective mechanism in a filling process allowing improvedprotection of the downstream isolation valve.

The arrangement of the dust-prevention valve and of the movable filterinteracts easily with various packaging connectors. Specifically, thedust-prevention valve and the movable filter move to allow opening ofthe upstream of the coupling while

-   -   protecting the downstream isolation valve from particles and    -   allowing the actuation of this downstream isolation valve by        mechanical contact.

The arrangement of the dust-prevention valve and of the movable filteralso interacts easily with packaging connectors opening the isolationvalve via a stream of pressurized gas delivered into the coupling(instead of a mechanical contact).

The arrangement of the coupling with double valves and movable filterthus provides a high level of protection of the isolation valve againstdirt and offers opening sequences that are suitable for various types offilling.

The invention provides great safety in the opening/closing sequences ofthe filler coupling. Moreover, filling according to the invention keepsthe coupling sealed throughout the life of the coupling.

Therefore, for example, and without being limiting, the upstreamdust-prevention valve can advantageously participate in the mechanicalopening of the downstream isolation valve by transmitting an openingforce from upstream to downstream. That is to say, in certain fillingconfigurations, the dust-prevention valve can form a member fortransmitting movement between a packaging connector and the downstreamisolation valve.

Similarly, the dust-prevention valve and the movable filter can ensurean opening of the upstream of the coupling allowing the downstreamisolation valve to be opened with the pressure of the filling gas (as afunction of the pressures and setting of the valves).

The upstream dust-prevention valve can therefore perform the followingfunctions:

-   -   the opening/closing of the upstream of the circuit,    -   the filtration of the stream upstream of the downstream        isolation valve during a filling process, and, optionally,    -   the transmission of mechanical movement in order to selectively        control the opening or closing of the downstream isolation        valve.

According to possible particular features:

-   -   the dust-prevention valve comprises a downstream end and, when        said dust-prevention valve is in a determined downstream        position called “contact” position opening the upstream end of        the circuit, this downstream end of the dust-prevention valve        pushes an upstream end of the movable isolation valve in order        to move the isolation valve to its downstream position for        opening the circuit,    -   the coupling comprises one or more passageways for guiding at        least a portion of the stream of fluid travelling from upstream        to downstream through the filter,    -   the body of the dust-prevention valve slides in the circuit, the        passageway or passageways constricting the totality or virtual        totality of the fluid stream travelling from upstream to        downstream in the circuit to travel through the filter        irrespective of the downstream position of the dust-prevention        valve,    -   when the dust-prevention valve is in a determined downstream        position called “contactless” position opening the upstream end        of the circuit, the downstream end of the dust-prevention valve        does not push the upstream end of the isolation valve, the        upstream end of the isolation valve being capable of being        pushed to its downstream position for opening the circuit by the        pressurized fluid entering through the open upstream end of the        circuit,    -   the isolation valve can be moved selectively into a downstream        position for opening the circuit by mechanical actuation carried        out by the dust-prevention valve,    -   the isolation valve can be moved selectively into a downstream        position for opening the circuit by a pressurized fluid stream,    -   the dust-prevention valve can be selectively moved downstream by        a mechanical actuation and/or by pressurized fluid,    -   the filter comprises at least one filter for gas designed to        trap solid particles,    -   the dust-prevention valve comprises an upstream end that can be        actuated mechanically and/or via pressurized fluid,    -   the movable isolation valve comprises a flexible sealing gasket        designed to interact with the seat in order to achieve the        sealed closure of the circuit when the valve is moved against        the seat with a determined pressure,    -   in the upstream position for closing the upstream end of the        circuit, said dust-prevention valve closes off in a sealed        manner the inlet orifice of the circuit upstream end, for        example, in a watertight manner,    -   in the upstream position for closing the upstream end of the        circuit, said dust-prevention valve closes off in an unsealed        manner the inlet orifice of the circuit upstream end,    -   the body of the coupling and/or the dust-prevention valve        comprises a flexible lip forming a watertight barrier between        the body of the coupling and the dust-prevention valve at least        when the latter is in the upstream closed position,    -   the flexible lip comprises a free end allowing a gas or liquid        to pass when a determined pressure differential exists on either        side of the lip, in order notably to allow a possible discharge        of gas from downstream to upstream, for example in the event of        leakage of the isolation valve,    -   in the upstream position of the dust-prevention valve, the        upstream end of the dust-prevention valve recloses the upstream        end of the circuit in a flush manner at the upstream end of the        body of the coupling,    -   the body of the dust-prevention valve slides in a sealed manner        in the circuit,    -   the sealing between the dust-prevention valve and the body of        the coupling is achieved by metal/metal contact and/or via at        least one seal,    -   the passageway(s) comprise one or more internal ducts passing        through the body of the dust-prevention valve and/or passing        through the body of the coupling,    -   the passageway(s) comprise at least one space between the        dust-prevention valve and the body of the coupling in order to        force all or virtually all of the fluid stream passing from        upstream to downstream in the circuit to pass through the        filter,    -   the return member moving the isolation valve to its upstream        position comprises at least one of the following: a compression        spring, a tension spring,    -   the return member moving the dust-prevention valve to its        upstream position comprises at least one of the following: a        compression spring,    -   the downstream end of the dust-prevention valve comprises a rod        for mechanically actuating the upstream end of the isolation        valve,    -   the upstream end of the isolation valve comprises a surface        designed to interact in mechanical contact with the downstream        end of the dust-prevention valve,    -   the isolation valve is closed before the closure of the        dust-prevention valve,    -   the filter comprises at least one of: felt, a sintered metal, a        metallic or nonmetallic mesh, a structure with agglomerated        metallic or nonmetallic beads, metallic or nonmetallic threads,    -   the filter is moved with the dust-prevention valve during the        operations of opening and closing said valve,    -   the filter is placed on the dust-prevention valve downstream of        the upstream end of said valve,    -   the filter is not subjected to a direct mechanical contact from        a valve driver when the dust-prevention valve is driven        downstream by a valve driver of a filling connector,    -   the seat of the isolation valve is formed by a shoulder of a        tubular frame secured to the body of the coupling, the isolation        valve sliding in this frame, the downstream end of the        dust-prevention valve entering said frame when the        dust-prevention valve comes into the downstream position,    -   the coupling comprises an abutment designed to interact with the        dust-prevention valve in order to limit the maximum downstream        position of the latter,    -   the abutment designed to interact with the dust-prevention valve        in order to limit the maximum downstream position of the latter        is secured to the body of the coupling and/or to a frame secured        to the body and defining the seat of the isolation valve,    -   the isolation valve comprises a nonreturn mechanism generating a        force on the isolation valve and moving upstream when the latter        is subjected to a fluidic pressure in its upstream portion,    -   the nonreturn mechanism comprises a channel connecting the        upstream end of the isolation valve to a downstream chamber in        order to convert a fluidic pressure on the upstream portion of        the valve into a force on the downstream end of the isolation        valve tending to move said isolation valve into an upstream        closed position,    -   the nonreturn mechanism (“NRV”) comprises a determined        surface-area ratio between, on the one hand, the upstream end of        the isolation valve subjected to an upstream fluid and, on the        other hand, the downstream end of the isolation valve        communicating with the chamber, in order to move said isolation        valve into an upstream closed position when its upstream end is        subjected to pressurized fluid.

The invention also relates to a tap for pressurized fluid, in particularfor pressurized gas, with or without pressure relief valve, comprising afiller coupling designed to interact with a packaging connector in orderto allow the filling of said receptacle via said coupling, the fillercoupling conforming with any one of the features above or below.

The invention also relates to a pressurized fluid receptacle, inparticular a pressurized gas bottle, comprising a tap conforming withany one of the features above or below.

The invention also relates to a method for filling a pressurized gasreceptacle conforming with any one of the features above or below bymeans of a packaging connector mechanically connected in a removablemanner to said connector for filling the receptacle, the methodcomprising a first step of moving the dust-prevention valve and thefilter to a downstream position for opening the upstream end of thecircuit via a mechanical actuation and/or a fluidic actuation carriedout by the packaging connector and a second step of moving the isolationvalve to a downstream opening position via a mechanical actuationcarried out by the dust-prevention valve and/or via a fluidic actuationcarried out by the packaging connector.

According to other possible particular features,

-   -   the dust-prevention valve is moved downstream by a mechanical        action of an end of a valve driver belonging to the packaging        connector,    -   at the end of the process for filling a pressurized gas        receptacle, the isolation valve is automatically closed when the        mechanical force and/or the fluidic force exerted on the        upstream portion of the valve becomes less than a determined        threshold,    -   the external and/or internal surface of the body of the coupling        comprises stampings forming attachment recesses and/or reliefs        designed to interact with paired shapes of a packaging connector        to form a selective mechanical attachment system, notably a        quick connection system,    -   the filling method comprises a first step of moving the        dust-prevention valve and the filter to a downstream position        for opening the upstream end of the circuit via a mechanical        actuation and/or a fluidic actuation carried out by the        packaging connector and a second step of moving the isolation        valve to a downstream opening position via a mechanical        actuation carried out by the dust-prevention valve,    -   the valve or valves can be opened independently of the        mechanical attachment of the packaging connector to the        coupling, in particular, the valve or valves can be opened by        the packaging connector after the mechanical attachment of the        packaging connector to the coupling and via a distinct actuation        of the attachment system,    -   the packaging connector designed to interact with a filler        coupling of a pressurized fluid receptacle tap comprises at        least one gripper extending in a longitudinal direction about a        longitudinal axis, the central space situated between the        gripper or grippers and the longitudinal axis forming a housing        designed to accommodate a filler coupling of generally        cylindrical shape, the internal face of the at least one gripper        situated facing the central space comprising reliefs and/or        recesses of determined dimensions, the reliefs and/or recesses        being spaced relative to one another in a determined manner in        order to fit into grooves and/or paired reliefs formed on the        external face of a filler coupling, the at least one gripper        being able to move transversely relative to the longitudinal        axis between a position called “outspread” in order to allow the        insertion of a coupling into the central space and a position        called “closed” to allow the fitting of the internal face of the        grippers on the external face of a coupling, said connector        comprising a locking member that can move between an active        position immobilizing the grippers in the closed position and an        inactive position allowing the grippers to move toward the        outspread position.

BRIEF DESCRIPTION OF THE FIGURES

The invention may also relate to any alternative device or methodcomprising any combination of the features above or below.

Other particular features and advantages will appear on reading thefollowing description made with reference to the drawings in which:

FIG. 1 represents a schematic view in section illustrating a firstexemplary embodiment of a filler coupling according to the invention ina closed position,

FIG. 2 represents a schematic and partial view in section illustratingthe filler coupling of FIG. 1 mounted on a receptacle tap in a positionopened by the action of a packaging connector,

FIG. 3 represents a schematic and partial view in section illustratingthe structure of a filler coupling according to the invention in aclosed position (two valves closed),

FIG. 4 represents the filler coupling of FIG. 3 in an open position (twovalves opened by mechanical contact),

FIG. 5 represents the filler coupling of FIG. 3 in an open position (twovalves opened respectively by gas pressure and by mechanical contact),

FIG. 6 represents the filler coupling of FIG. 3 in an open position (twovalves opened respectively by mechanical contact and by gas pressure),

FIG. 7 represents the filler coupling of FIG. 3 in an open position (twovalves opened by gas pressure),

FIG. 8 represents a schematic view in section illustrating a secondexemplary embodiment of a filler coupling according to the invention ina closed position,

FIG. 9 represents an enlarged view in section of a detail of theupstream end of a filler coupling illustrating another possibleexemplary embodiment of the upstream valve in the closed position),

FIG. 10 represents the filler coupling of FIG. 3 in a closed testposition (upstream valve open and downstream valve closed).

DETAILED DESCRIPTION OF THE INVENTION

Now with reference to FIG. 1, the filler coupling 1 comprises a body 2,for example of generally cylindrical shape. The body 2 defines aninternal filling circuit 6 between an upstream end 3 designed to beconnected to a packaging connector and a downstream end 4 designed to beconnected to a pressurized gas receptacle (via for example an internalcircuit of a tap).

The terms “upstream” and “downstream” define the flow of a filling gasfrom a packaging connector to the inside of a receptacle.

The upstream end 3 of the circuit 6 (and of the coupling 1) can beselectively closed by a dust-prevention valve 10 which can move in thebody 2 of the coupling.

The dust-prevention valve 10 can be selectively moved in the body 2(preferably in translation) between an upstream position for closing theupstream end 3 of the circuit 6 and a downstream position for openingthe circuit upstream end 3. Preferably, the dust-prevention valve 10 ismoved to its upstream position by a return member 14, for example aspring such as a compression spring.

Preferably, in the upstream position for closing the upstream end 3 ofthe circuit 6, the dust-prevention valve 10 is housed in the body 2 ofthe coupling and is flush with the end surface of the body 2 of thecoupling 1.

The dust-prevention valve 10 closes the upstream inlet 3 of the circuitin a sealed or unsealed manner by contact with the body 2 of thecoupling 1. The body of the dust-prevention valve 10 may comprise one ormore seals 105 closing off the circuit 6 in a sealed manner.

The dust-prevention valve 10 moreover supports a filtering element suchas one or more filters 102 designed to trap solid particles having adimension greater than a determined threshold. For example, the filteror filters 102 trap the particles that have dimensions greater than 0.1mm or greater than 0.05 mm or greater than 1 mm or greater than 1 mm orgreater than 2 mm or greater than 3 mm (depending on requirements ordepending on the applicable standard: medical or industrial). Naturally,the invention is not limited to these precise examples and the filtermay be designed to trap particles of a smaller or larger size than theabove examples.

The filter 102 comprises for example at least one amongst: felt, aporous structure made of sintered metal, one or more metallic and/ornonmetallic meshes, a porous structure with agglomerated metallic ornonmetallic beads, metallic or nonmetallic threads or any otherappropriate filter according to the application (as a nonlimitingexample, see the filters from “Copor”).

The filter 102 can be moved with the dust-prevention valve 10. Thefilter 102 is interposed on the path of at least a portion of the fluidthat travels between the upstream 3 and the downstream 4 of the circuit6.

Accordingly, the dust-prevention valve 10 may comprise one or morepassageways 103 guiding at least a portion and preferably all of thefluid stream travelling from upstream 3 to downstream 4 through thefilter 102. That is to say that, when a gas travels from upstream 3 todownstream 4, the passageway(s) 103 force the totality or the virtualtotality of the gas stream to pass through the filter 102 irrespectiveof the downstream position of the dust-prevention valve 10. Thepassageways 103 may comprise internal ducts passing through the body ofthe valve 10. As a variant or in combination, it is possible to envisageducts or passageways passing through the body 2 of the coupling 1.Similarly, as a variant or in combination, it is possible to envisageone or more passageways 103 formed by a spacing between thedust-prevention valve 10 and the body 2 of the coupling.

The clogging of the filter 102 can be limited by subjecting the filter102 to bleeding streams (from downstream to upstream). This can notablybe provided during a filling operation or before a filling. In thismanner, the filter 102 can be cleared of at least a portion of theparticles trapped in the filter during a previous filling.

The filter 102 can be attached removably or irremovably to thedust-prevention valve 10. For example, the filter 12 is crimped into thebody of the dust-prevention valve 10. It is possible to envisage thefilter 102 being removable and replaceable. For example, the filter 102is replaced or cleaned according to a maintenance procedure periodicallyin order to discharge the trapped dust or impurities and thus ensurethat the isolation valve 7 downstream is protected at all times (inorder also to limit the risks of adiabatic compression for example). Asa variant, to change filter, the dust-prevention valve 10 can bereplaced. As a variant, the coupling is replaced in its entirety.

Downstream of the dust-prevention valve 10, the circuit 6 contains anisolation valve 7 that can move relative to a seat 8. The isolationvalve 7 can be moved preferably in translation between an upstreamposition for closing the circuit and a downstream position for openingthe circuit. The isolation valve 7 is moved by default toward itsupstream position by a return member 9 such as a spring notably acompression spring.

As shown, the isolation valve 7 may comprise a flexible sealing gasket17 designed to interact with the seat 8. The flexible gasket may containplastic, a polymer, a cured elastomer or any other appropriate material.

As shown, without it being necessary, the seat 8 of the isolation valve7 can be formed by an annular shoulder secured to a tubular frame 15fixed in the body 2 of the coupling (for example by sealed screwing).For example, the isolation valve 7 slides in this frame 15. One end 16of this frame 15 or of the seat 8 can for example form an abutment 16designed to interact with the dust-prevention valve 10 to limit themaximum downstream position of the latter. Similarly, the spring 14 ofthe dust-prevention valve can rest on this frame 15.

Therefore, the dust-prevention valve 10 comprises an upstream end orsurface 104 that can be actuated mechanically (that is to say bymechanical contact) and/or via pressurized fluid.

Preferably, the filter 102 is placed on the dust-prevention valve 10downstream of the upstream end 104 of said valve 10. In this way, thefilter 102 is not directly subjected to a mechanical contact or to apressure when the dust-prevention valve 10 is pushed downstream.

In FIG. 2, the coupling 1 is shown schematically on a tap 12 of areceptacle 13. Moreover, a packaging connector 11 opening the coupling 1is shown symbolically in dashed lines.

Preferably, the external surface of the body 2 of the coupling 1comprises stampings 116 forming attachment recesses and/or reliefsdesigned to interact with paired shapes of a packaging connector 11 inorder to form a mechanical attachment system, notably a quick connectionsystem (not shown in detail). In particular, preferably the stampings116 are of a dimension and are positioned according to a determinedgeometry preferably in order to fit a determined paired packagingconnector 11 (and only that connector).

As shown in FIG. 2, the dust-prevention valve 10 can be movedselectively downstream by a mechanical actuation, for example by a valvedriver 111 that can be moved selectively in response to an actuator suchas a pivoting lever 204 for example. The movement of the valve driver111 can be obtained also automatically, for example pneumatically orand/or by an electromechanical system.

The valve driver 111 is preferably inserted into the coupling in asealed manner and delivers pressurized gas via an internal or externalchannel to the valve driver 111 (not shown).

As can be seen in FIG. 2, when the dust-prevention valve 10 is broughtto a determined downstream position called the “contact” position (withthe upstream end 3 open), a downstream end 101 of the dust-preventionvalve 10 pushes an upstream end 107 of the isolation valve 7 in order tomove the isolation valve 7 toward its downstream position for openingthe circuit 6.

That is to say that the isolation valve 7 can be moved selectively intoa downstream position for opening the circuit by mechanical actuationcarried out by the dust-prevention valve 10.

Accordingly, as shown in the figures, the dust-prevention valve 10 maycomprise a downstream end 101 in the form of a rod the terminal surfaceof which is designed to mechanically actuate the upstream end of theisolation valve 7. The upstream end of the isolation valve 7 may also beformed by a rod which protrudes in the upstream direction relative tothe seat 8 of generally annular shape.

Therefore, from a closed position (dust-prevention valve 10 closed F andisolation valve closed F) illustrated schematically in FIG. 3, apackaging connector 11 can mechanically push the upstream end 104 of thedust-prevention valve 10 (pressure P). The dust-prevention valve 10 andthe filter 102 are moved in the downstream direction. The inlet of thecircuit 6 of the coupling 2 is open (FIG. 4). The downstream end 101 ofthe dust-prevention valve 10 in its turn pushes the upstream end 107 ofthe isolation valve 7 (mechanical pressure P) which then opens thedownstream end of the circuit 6. The stream of pressurized gas cantravel from upstream to downstream (symbolized by the arrows).

Naturally, this method of opening and of filling is not limited to thisexample. Therefore, as shown in FIG. 5, depending on the fillingconditions, the upstream end 104 of the dust-prevention valve 10 can bepushed in the downstream direction by the gas stream itself (symbolizedby arrows). The downstream end 101 of the dust-prevention valve 10 canthen mechanically push (pressure P) the isolation valve 7.

In the variant of FIG. 6, the dust-prevention valve 10 is opened (O)mechanically by a packaging connector 11 (pressure P) but the isolationvalve 7 is opened (O) not by the downstream end 101 of thedust-prevention valve 10 but by the force exerted by the pressure of theincoming gas.

In the variant of FIG. 7, the dust-prevention valve 10 and the isolationvalve 7 are opened (O) by the force exerted by the pressure of thefilling gas.

Therefore, it is easy to understand that, depending on the geometry ofthe filling connector and the filling conditions (notably the flow rateand the pressure of the filling gas inserted into the coupling by thefilling connector 11), the two valves 10, 7 in series can be opened(moved in the downstream direction) by a mechanical contact and/or bythe pressure of the filling gas.

This confers great flexibility of use on the coupling according to theinvention. Specifically, filling with gas in all cases ensures that thegas is filtered upstream of the isolation valve 7. Moreover, the filter102 does not oppose the mechanical actuation of the dust-preventionvalve 10.

Moreover, the opening of the coupling when filling can be obtained by asequential opening of the two valves 10, 7 in series (first thedust-prevention valve 10, then the isolation valve 7).

At the end of a filling process of a pressurized gas receptacle, theisolation valve 7 is closed automatically by the action of the spring 9when the mechanical and/or fluidic force exerted on the upstream portionof the valve 7 falls below a determined threshold. At the end of thefilling operation, the isolation valve 7 is closed in principle beforethe dust-prevention valve 10 is closed.

The structure according to the invention also makes it possible to putin place filling procedures that are particularly effective in terms ofsafety for the operators carrying out the filling and for the end usersof the tap fitted with such a coupling.

Therefore, for example, the movable dust-prevention valve 10 adopts,during its movement, at least two sealed positions making it possible toensure secure filling.

In a first sealed position, the dust-prevention valve 10 is moved in thedownstream direction and opens the upstream of the circuit 6 without theisolation valve 7 being opened (see FIG. 10). In this open position (O)of the upstream valve 10 and the closed position (F) of the downstreamvalve 7, the chamber situated upstream of the isolation valve 7 can beevacuated (determined low pressure) for example by a filling tool inorder to carry out tests prior to filling. In this configuration, it isactually possible to measure any leaks originating from the isolationvalve 7.

In another sealed position, the isolation valve 7 can also be opened inorder to carry out a filling and/or to carry out a possible emptying ofthe circuit 6 and of the bottle before filling (see for example theconfiguration of FIG. 4, but with a gas stream reversed in the event ofdraining).

At the end of filling, the isolation valve 7 can be closed again and thedust-prevention valve 10 can be kept open (see FIG. 10) to carry outpossible sealing tests at the end of filling such as those describedabove prior to filling.

FIG. 8 illustrates a variant embodiment of the invention which differsfrom that described above only in that the isolation valve 7 comprises anonreturn mechanism 7, 177 (“NRV”=“nonreturn valve”).

For the purposes of being concise, the same elements as those describedabove are indicated by the same reference numbers and are not describeda second time.

The nonreturn mechanism 7, 177, known per se, comprises a systemgenerating a force on the isolation valve 7 pushing it upstream when thelatter is subjected to a fluidic pressure in its upstream portion.

That is to say that the nonreturn mechanism 7, 177 is designed to allowthe isolation valve 7 to be opened only by pressure via a mechanicalcontact (and not via a fluidic pressure).

The nonreturn mechanism comprises for example a channel 77 connectingthe upstream end 107 of the isolation valve 7 to a sealed downstreamchamber 277. This architecture converts a fluidic pressure on theupstream portion 107 of the valve 7 to a force on the downstream end ofthe isolation valve 7 tending to move said isolation valve 7 into anupstream position for closure. Accordingly, the nonreturn mechanismcomprises a determined ratio of surface areas between, on the one hand,the upstream end 107 of the isolation valve 7 subjected to an upstreamfluid and, on the other hand, the downstream end of the isolation valve7 communicating with the chamber 277. In this way, the isolation valve 7is moved into an upstream position for closure when its upstream end issubjected to pressurized fluid.

A method of filling via the coupling of FIG. 8 may comprise a first stepof moving the dust-prevention valve 10 and the filter 102 to adownstream position for opening the upstream end of the circuit 6 via amechanical actuation and/or a fluidic actuation. On the other hand, theisolation valve 7 can be opened only mechanically by a pushing forcemade by the dust-prevention valve 10.

These filling methods make it possible to ensure safe filling and themaintained sealing of the coupling after many fills.

The variant of FIG. 9 differs from that of FIG. 1 only in that the body2 of the coupling 1 comprises a flexible lip 27 the free end of whichinteracts with the dust-prevention valve 10 in order to form awatertight barrier between the body 2 of the coupling and thedust-prevention valve 10 (at least when the latter is in the upstreamclosed position).

The flexible lip 27, which preferably has an annular shape around thedust-prevention valve 10, is for example made of elastomer fitted orcured onto the body 2.

The flexibility of the lip 27 is designed to prevent ingress of water inthe downstream direction while all the same allowing fluid (gas notably)to pass in the event of determined pressure (notably in the event ofleakage of the isolation valve 7).

The use of this coupling on gas taps preferably furnished with pressurerelief valves offers many advantages. Specifically, the gas receptacles(bottles for example) furnished with such taps can be filled in totalsafety and can retain one and the same filler coupling withoutendangering the seal of the coupling.

The filling method according to the invention therefore makes itpossible to improve the protection of the sealing valve gasket fromcontamination (metal particles, dust etc.) via the movable filter thatis moved during filling.

This makes it possible to increase the reliability of the seal of thecoupling throughout the life of the tap and of the bottle fittedtherewith.

According to the invention, the mechanical pushing of the isolationvalve 7 remains possible despite the presence of the filter 102upstream.

Irrespective of the presence of a movable filter on the dust-preventionvalve 10 (the filter can be omitted), the filling method according tothe invention therefore makes it possible to improve the safety offilling via the actuation of the in-series double-valve mechanismdescribed above.

Advantageously the invention applies to the filler couplings and fillingsystems for pressurized gas bottles, for example between 150 and 750bar, fitted with taps with integrated relief valves or with removablerelief valves.

In a possible variant, the movable filter could be omitted from thedust-prevention valve 10.

The filler coupling may if necessary also be the gas drainage coupling.

It will be understood that many additional changes in the details,materials, steps and arrangement of parts, which have been hereindescribed in order to explain the nature of the invention, may be madeby those skilled in the art within the principle and scope of theinvention as expressed in the appended claims. Thus, the presentinvention is not intended to be limited to the specific embodiments inthe examples given above.

What is claimed is:
 1. A filler and withdrawal coupling for apressurized gas receptacle designed to interact with a packagingconnector in order to allow said receptacle to be filled and for gas tobe withdrawn, the coupling comprising a body defining an internalwithdrawal circuit between an upstream end adapted to be capable ofconnecting to a packaging connector and a downstream end adapted to becapable of connecting to a receptacle, the coupling comprising anisolation valve that is capable of moving relative to a seat between anupstream position capable of closing the internal withdrawal circuit anda downstream position capable of opening the internal withdrawalcircuit, said isolation valve adapted to be moved to its upstreamposition by a return member, the coupling also comprising adust-prevention valve placed upstream of the isolation valve, saiddust-prevention valve being capable of moving relative to the bodybetween an upstream position capable of closing the upstream end of theinternal withdrawal circuit and a downstream position capable of closingopening the internal withdrawal circuit upstream end, saiddust-prevention valve capable of closure by being moved to its upstreamposition by a return member, wherein the dust-prevention valve comprisesa filter interposed on the path of at least a portion of the internalwithdrawal circuit, the filter being adapted to move with thedust-prevention valve.
 2. The coupling as claimed in claim 1, whereinthe dust-prevention valve comprises a downstream end and saiddust-prevention valve is capable of occupying a contact position whereinthe downstream end of the dust-prevention valve is capable of operablyinteracting with an upstream end of the movable isolation valve tothereby move the isolation valve to its downstream position therebyopening the internal withdrawal circuit.
 3. The coupling as claimed inclaim 1, wherein one or more passageways are adapted to guide at least aportion of a stream of fluid travelling from upstream to downstreamthrough the filter.
 4. The coupling as claimed in claim 3, wherein thebody of the dust-prevention valve is capable of sliding in the circuitand the passageway or passageways are adapted to constrict the totalityor substantial totality of a fluid stream travelling from upstream todownstream in the internal withdrawal circuit and are further adapted todirect the fluid stream through the filter irrespective of thedownstream position of the dust-prevention valve.
 5. The coupling asclaimed in claim 1, wherein the dust-prevention valve is adapted to becapable of occupying a contactless position, the contactless positionconfigured to open the upstream end of the internal withdrawal circuit,the contactless position comprising a downstream end of thedust-prevention valve not in contact with the upstream end of theisolation valve, wherein the upstream end of the isolation valve iscapable of being pushed to its downstream position for opening theinternal withdrawal circuit by the pressurized fluid entering throughthe open upstream end of the circuit.
 6. The coupling as claimed inclaim 1, wherein the isolation valve is capable of being movedselectively into a downstream position for opening the circuit by amechanical actuation by the dust-prevention valve.
 7. The coupling asclaimed in claim 1, wherein the isolation valve is capable of beingmoved selectively into a downstream position for opening the circuit bya pressurized fluid stream.
 8. The coupling as claimed in claim 1,wherein the dust-prevention valve is capable of being selectively moveddownstream by a mechanical actuation and/or by pressurized fluid.
 9. Thecoupling as claimed in claim 1, wherein the filter comprises at leastone filter for a gas and is adapted to trap solid particles in the gas.10. A tap for pressurized fluid, comprising the coupling of claim 1 andadapted to interact with a packaging connector in order to allow thewithdrawal of gas from said receptacle via said coupling.
 11. Apressurized gas receptacle, comprising the tap of claim
 10. 12. A methodfor withdrawing gas from the pressurized gas receptacle of claim 11 by apackaging connector mechanically connected in a removable manner to saidconnector for withdrawal of gas from the receptacle, wherein the methodcomprises a first step of moving the dust-prevention valve and thefilter to a downstream position for opening the upstream end of thecircuit via a mechanical actuation and/or a fluidic actuation carriedout by the packaging connector and a second step of moving the isolationvalve to a downstream opening position via a mechanical actuationcarried out by the dust-prevention valve and/or via a fluidic actuationcarried out by the packaging connector.
 13. The method as claimed inclaim 12, wherein the dust-prevention valve is moved downstream by amechanical action of an end of a valve driver belonging to the packagingconnector.
 14. The method as claimed in claim 1, wherein at the end ofthe process, the method comprises a further step of automaticallyclosing the isolation valve when the mechanical force on and/or thefluidic force exerted on the upstream portion of the valve becomes lessthan a determined threshold.
 15. The method as claimed in claim 1,wherein the external and/or internal surface of the body of the couplingcomprises stampings forming attachment recesses and/or reliefs designedto interact with paired shapes of a packaging connector to form aselective mechanical attachment system.
 16. The method as claimed inclaim 1, wherein the method comprises a first step of moving thedust-prevention valve and the filter to a downstream position foropening the upstream end of the circuit via a mechanical actuationand/or a fluidic actuation carried out by the packaging connector and asecond step of moving the isolation valve to a downstream openingposition via a mechanical actuation carried out by the dust-preventionvalve.